Bloch pleaded guilty last year to withholding information from a House oversight committee that was investigating what he claimed was the accidental deletion of files on government computers being sought by investigators examining whether Bloch improperly forced out former OSC employees.
Both legal teams argued that the law for contempt of Congress can be punishable with a term of no less than one month, but that the sentence is not mandatory.
In her ruling, however, Magistrate Judge Deborah Robinson wrote that Congress "expressly provided for a mandatory minimum sentence of one month... that the language by which it did so is unambiguous; and that no authority permits the court to disregard the provision, or to interpret it other than in accordance with its plain meaning."
The sentencing comes more than a week after OSC released a report concluding an investigation begun by Bloch, which found that White House and Cabinet officials in the Bush administration violated laws against political activity by federal employees. Critics of the investigation argue that Bloch's sentencing undermines the legitimacy of the probe.